Discharge-valve.



C. G. SPRADO. DISCHARGE VALVE. APPLIUATION FILED 00T. 2v, 1911.

Patented Jung 18, 1912.

WET--6- ITNESSEE- ATTCHQNEY.

, citizen ofs the United States, residing at,

' .f UNITED sTA'rEsrnfrENT oFFron.

gcnm. e. srnAno, or mLwAUKEE, WISCONSIN, AssIGNon To ALLIS-CHALMERS cont- PANY.- or MILWAUKEE, WISCONSIN, A; comomvrron or NEW JERSEY.

DISCHARGE-VALVE. y

' Specification of Letters Patent. Patented J 18, 1912.

Application led October' 27, 1911. Serial No. 657,173.

To all w'lzom it may concern:

Be it known that I, CARL G. SPRADO, a

Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a certain new and useful Improvement 4in Discharge- I Valves,` of which the following is a specifica- This invention relates to /improvements in the construction of'air discharge valves for high speed blowing engines.

The object of the invention is to provide arr air discharge valve `for blowing engines,

which is simple inyconstruction,efficient in operation, and which is particularly adapted to operate under.' high-pressure and at valves 4.

- high-Speeds.

' gviding an bndinaryflapfvalve with ,an initial set ayvayffrom' its seat so that the valve in closing will have van linrolling motion onA the seat, thereby retarding the velocity with which the valve strikes.

' the same or similar A clear conception of several embodi ments of the inventionmay be had b y reof the device being shown -in section, the

section being taken along the line 2 2 of Fig. llooklng ,in the direction of.' the arrow. Figs. 3, 4, 5 and 'disclose central sections through yfragment-s of modied forms of valve cages, valves and valve lstops.

The blowing 4engine/valve cage 3, which is adapted. to be secured in the blow/,ing

engine cylinder head inthe usual manner,

\ has a hexagonal portion. the louter surfaces vof which form a series of valve seats. Ports'- 5 connect the interior of the cage 3, .which is normally in open communication wit-hjthe' interior ofthe vblowingc linder, With'thedischarge chamber hic normally surrounds the hexagonal ortion of, the cage 3.

Grooves 6 are formedinthe portions ofthe valve .seats intermediate the 'Orts 5, and serve to relieve the suction Valves 'and Itheir seats during opening.

The invention consists essentially-in prorent ' of sheet metal and have a natural bias posithereforefbe said to have an initial set away from their respective seats. The valve -stops 1 have curved surfaces ontheirl sides adjacent the ap valves 4 and are secured tothe tions which project bet-Ween the clamping y3, thus providing securing means for the During the vnormal operationof the'comchamber which'surrounds the valve cage 3', tends to keep the valves 4against the adjacent valve seats formed on the cage'3. As the pressure withinthe cage 3v is, by the forward motion of the piston of the blowing engine, brought up to a pressure substantially equal to that in the discharge'cham- ,4 causes these valves vto take the position F'shown in Fig. 1. Any increase in the Apressure within the cage 3 will, after such pochamben Such passage ofair'through the ports 5 will cause Ithe valves 4 to be opened Still farther until they contact with the .curved surfaces of theiradjacent valve stopsA 1. As the pressure within the cage 3' decreases, the valves-4 recede from their corresponding stops 1, being eventually brought. in Contact with their .seats by the In`the`forrn of. the invention disclosed in Fig. 3, the valve cage 13 is provided with concavely curved valve seats instead of The valves 14 are cnv'exly curved toward their adjacent seats andare rprovided with convexlycurved stops 11. he valves 14 are Aso` formed thatxtheir curvature of. convexity is greater than the curvature of con- -the valves 14 ari-initial` sety away trom-t eir seats, while" ,in inactive position,` as shown. In the' form offinventiondlsclosed `1n F1g.

' tween the 4, thevalvecage 31'is provided `with con- The ilap valves 4 are preferalbly formedJ tioning them away from their seats being convexly.. 4curved relative to their. plane surfaceslo'f the ,valve stops land the cagey presser, the high pressure' in the discharge ber, the'initial set or curvaturefof the valves sitioning of the valves 4, cause the air fromY `within the cage Sito ow intothedischarge cavity 'of' their adjacent seats, thus giving vez'rly curved seats adjacent the ports 15.,l

cage 3. by any suitable means, as4 by `machine screws 2. The valves 4i have end por.

highpressure within the discharge chamber.

plane seatsas disclosed in Figs. 1. and 2.V

\ The valves k16 areconvexly curved toward their adjacent seats and are provided with convexly curved stops 21. By forming 'the valves 16 withconvex seating surfaces ad' 5 jacent con'vexl'y curved seats on the cage 31',

1()4 Fig. 5, th'e valve cage 4l is provi ed withv convexly curved lseats adjacent the ports 17. The valves-l`8 are formed with plane seating surfaces and have convexly curved adjacent stop 22.

jacent valve seats convexly curved, the

valves 18 have an initial set away from their seats while in inactive position, as shown.

Inthe form of the invention disclosed in 2O Fig. 6, the valve cage 51 is provided with stopping surfaces or the valves, QOl The valves 20 are so formed that their curvature ofA concavity is lessthan the curvature lof convexity`of the adjacent seats, thus giving the valve 20 an initial set away from their seats while in hinactive position, as shown.

It will be noted"that by giving the valves aninitial set away from their seats, the valves while seating will be brought gradually against their seats,y the outer free ends of the valves being the last portions thereof to contactwith the' seats. In this way the v alves may be said to have an unrolling Inotlon which tends to bring the seating surface of the valve intoradual contact with 4l) the seat, thereby retardingthe velocity with which the valves strike their seat. f.- In opening, the valves are partially opened at the instant the pressure within the piston cham-l ber balances the pressure Within the discharge chamber, thereby permitting discharge of the air from within the blower cylinder at the most effective moment. The curvature of the valves in opening as in closing thereof, will tend to retard the velocity with which the valves strike their adjacent valve stops. This eect is brought about in'the opening of the valves by formmg the stop surfaces'of the valve stops of slightly greater curvature than the adjacent surfaces `of the valves.l j

vIt should be notedu that with the valves constructed with an initial set and operating as above describeda construction well f adapted to operate under high pressures andhigh speeds 1s provided, since such construction of the valves reduces the 'pounding or lmpact of the valves againsttheir seats to a minimum.

By forming the valves v123V 15 with plane seating surfaces andthe ad- Since it is rather diilicult to formy a valve seat` .having a curved seating surface, it

would probably be preferable in most-cases l to use the construction disclosed in Figs. 1 and 2,v although applicant does not 'desire'to limitthe scope of -his invention to such construction. All' of the forms of the invention disclosedwould be .equally eficient in operation, 'since in each case the valve has an initial set away from vits adjacent valve seat. j

It should be understood that it is not desired to be limitedto the exact details of construction shown and described, for obvious modiiications will occur to a person e skilled in the art.-

It is claimed anddesired to secure by Let- 1. In a blowing engine, a valve, and a seat for sale valve, said valve having at one por tion thereof an Linitial set away from said seat whereby a free passage exists between said valve and seat when the pressures on 'opposite sides of the valve are equalized.

2. In. a blowing engine, a curved valve, and a plane seat for said valve, said valve having its 'curved portion free from engagement with said seatwhereby afree passage exists between said valve and seat when the pressures on opposite sides of the valve are equalized.

3. In a blowing engine, a sheetl metal valve, and aseat spaced from said valve, Said valve having a portion freev from engagement with said seat whereby a free passage exists between said valve and seat when the pressures on opposite sides of the valve are equalized.` A

4.v In. a blowing engine, a curved valve, and a'plane seat for said valve, said valve at one end being fastened to said seatand 'having its curved portion free from engagement with said seat when vthe .pressures on opposite'sides of the valve are equalized.

- 5. In a blowing engine, a valve, and a's'eat for said valve, said valve being fastened to said seat at one portion thereof and having at another portion Ikthereof an initial set away AfromA the seating surface. e

"16. In a blowing engine, a valve having a natural bias positioning same'away from its seating surface to form, at the time the pressures on opposite sides of the valve are ,equalized, a free passage permitting discharge between sai' valve arid seating surfacetl .l

In testimony whereof, the signature of the inventoris aiiixed hereto in the presence of two witnesses'. v C ARLG. SPRADO.l

Witnesses:

W. H. Linsen, R. F. Smrrn.

Correction in Letters Patent No. 1,029,726.

It is hereby certified that in Letters' Patent No. 1,029,726, granted June 18, 1912,

upon the application of Carl-G. Sprado, of Milwaukee, Wisconsin, for an improve ment in Discharge-Valves, an error appears in the printed .specification requiring v correction as follows: Page 2, line 83, for the Word sale, read said; and thatthe said Letters Patent should be read with this correction therein that the same may conform to the record of the oase in the Patent Office.

Signed and sealed this 23rd day of-July, A. D., 1912.

[SEAL] o. c. BILLINGS, A

Acting? Commissioner of Patents. 

